The 46-year-old singer hit headlines when she sent an hilarious text message to the Oscar-winning actor as part of a recent prank on James Corden's TV show Carpool Karaoke.

James composed the message, which read "Hey baby, I'm kind of feeling like I need to cut loose. Any suggestions? Let me know. J.Lo, you know, from the block", and sent it to Leonardo before Jennifer could stop him.

Speaking on Thursday night (31Mar16) after the American Idol show, Jennifer admitted she "did have to explain" the joke to The Revenant actor.

But luckily he saw the funny side.

"He was a great sport about it ... I was like, 'So hey, this is what had happened! I was with James Corden ...'" Jennifer said, according to Entertainment Tonight.

Jennifer added she hasn't spoken to Leonardo since the prank aired on Tuesday night (29Mar16) but doesn't think he holds a grudge about it.

"He's great. He's a friend and it was nice,” she added. “He was totally like, 'Do whatever you want, I don't care.' I don't know if he'd say that today!"

James was stunned by the star-studded contacts list in Jennifer's phone during the hour-long Carpool Karaoke primetime special.

When asked who the most famous person is in her phone, Jennifer pulled out her phone to show him names including Demi Lovato, Chris Brown, Bradley Cooper, and Dwayne 'The Rock' Johnson.

Footballer Cristiano Ronaldo got the most dramatic reaction from James though, who exclaimed: "Oh my God – hang on, I've got to pull in. This is the best phone I've ever seen in my life. This is insane. Fergie, Iggy Azalea."

James then found Oscar-winning actor Leonardo's number on the phone and proceeded to compose the text message.